Stop mechanism fob



1929. G. B. HODGINS 1,723,170

STOP MECHANISM FOR TALKING MACHINES Filed Nov. 25, 1927 2 sheets-sheet 1 (ferczfl 51% a 2:725

6, 1929- G. B. HODGINS 1,723,170

STOP MECHANISM FOR TALKING MACHINES Filed Nov. 25, 1927 2 Sheets-Sheet 2 Patented Aug. 6, 1929.

UNITED STATES GERALD B. HODGINS, OF MOSCOW, IDAHO.

STOP MECHANISM FOR TALKING MACHINES.

Application filed November 25, 1927.

My invention relates to mechanism for automatically controlling the operating means of talking machines at the completion of a record. The invention is applicable to many forms of machines and is not tov be construed as limited to the exact application shown and described, as it is applicable to both mechanically and electrically operated machines of this character, not only for stopping the playing of a record, but for setting in motion record changing or repeatlng apparatus as well.

It is a purpose of this invention to provide an automatic control mechanism of this character which is caused to operate by a change in the relation of the angular speed of the tone arm to the rotational speed of the record carrying means.

In the present records on the market, the

finishing groove of the record is usually of a spiral formation of greater pitch than the playing spiral groove, or is an eccentric groove. It is a purpose of this invention to provide a stop mechanism which operates equally well with either of the above mentioned types at the close of the playing of the record without previous adjustment regardless of the length of the record.

Another object of the invention is to provide a stop mechanism of this character which permits stopping and starting of the record at any point without interference with the automatic stopping at the end of the record.

It is also an object of this invention to provide stop mechanism of this character which permits the tone arm to be reset in any desired position after stopping without restarting the machine due to release of the stop mechanism.

A further object of this invention is to provide a stop actuating mechanism which after setting in motion the means for stopping the machine immediately and automatically resets itself so as to be in position to again actuate the stopping means if necessary.

Other objects and advantages of the invention will appear as the description proceeds in connection with the accompanying drawings wherein a specific application of the invention is illustrated.

In the drawings: Fig. 1 is a top plan view of the talking Serial No. 235,600.

machine with the tone arm broken away and the turntable rim only indicated, showing the stop mechanism;

Fig. 2 is a view showing the stop mechamsm in the act of applying the brake;

Fig. 3 is a bottom view of the stop mechanlsm;

Fig. 4 is a top view of a modified form of the invention; and

Fig. 5 is a top view of a further modification.

Referring now in detail to the drawings, in the embodiment illustrated a turntable T is shown mounted centrally on the driving post P and over which is mounted in the usual position a tone arm A which usually carries a reproducer and a post S extending downward from its underside commonly pro vided to operate stop mechanisms. These parts are of ordinary construction such as are usually found in talking machines and form no part of the invention.

The attachment constituting the invention is preferably mounted. on a metal plate 1 to be fastened on the motorboard beneath the turntable and comprises a worm 2 which is mounted on the center post P and which meshes with a worm gear 3 carrying on its shaft 4 a threaded portion 5, said worm gear shaft being supported in bearings attached to the plate 1 on which the mechanism is mounted.

A lever 6 is pivoted near its center on a pin 7 carried by the plate 1 so as to swing freely throughout its required range of motion for a purpose to be explained presently. This lever 6 is provided with a retaining arm 8, said arm 8 being in turn pivoted to the lever 6 at 9 and so constructed that when the mechanism is properly assembled the post S ordinarily attached to the tone arms of talking machines for operating brakes will be constantly held in contact with the edge 10 of lever 6 in all positions of the mechanism the preferred arrangement for accomplishing this being by'means of a spring 11, one end of which is attached to the retaining arm 8 and the other to the lever 6.

The other end of lever 6 carries a pivot 12 on which is mounted a link 13 for the pur' pose of supporting a dog 14 on a pivot 15 in such a manner that, as the lever 6 is moved by the tone arm, the tooth of the dog is caused to travel parallel to the axis of the shaft 4 and held constantly in contact with its surface. This is accomplished in the preferred arrangement indicated by extending the pivot on which the dog 14 is mounted through the lower side of the (legend into a slot 16 cut in plate. 17 which in turn is fastened rigidly to lever 18. The slot 16 is parallel to the axis of shaft 4 and hence the dog is caused to travel parallel to this shaft.

'1 A Weak coil spring 14 normally urges, dog

14 into engagement with. shaft 4.

Lever 18 is pivoted at one end 19,150 the plate 1 and is constantly drawn toward the post P by means of a suitable spring 20 attached to the lever 18 at 21 and to the 30, one end 31 of which is attached to the trigger 29, the, other end 32 being attached to plate 1 in the preferred arrangement. The range of movement of the trigger 29 is limited by the stops 33 and on the brake plate 26 to that necessary for the proper operation of the mechanism and is a stop which engages corner 24 of the lever 18 after the brake hasbeen applied. A brake shoe 36 is carried by a lip 37 on thebrake plate 26, said lip being so attachedto brake plate 26 that it is parallel to and overlaps the flange around the periphery of the turntable so as to allow the brake to be applied to the inner side of that flange when the brake is set.

In the use of this attachment, the parts are mounted as shown and the brake is automatically applied after" the ,record is finished inthe following manner. As: the turntable revolves while the record is being played, the needle in the reproducer follows in the spiral thread of said record and in turn causes the tone arm A to swing gradually toward post P about which the turntable revolves. As the tone arm A swings toward post P the post which it carries extending from its under side and which is held in engagement with edge 10 of lever 6 moves said lever 6 at a certain rate about its pivot 7,

thus causing the dog'14 to travel parallel to the axis of shaft 4 at a velocity equal to or slightly less than that with which a nonrotating nut on the threads of shaft 4 would advance. It is clear that as long as this relationship exists between the velocity at which L72a17o M slower than a nut would, then the spring 14 would permit it to pass over a thread of the shaft. I

When the needle in the reproducer reaches a point near the end of the record, it engages in either the eccentric groove or the sharply turned spiral in which the inner ends of the spiral grooves on talking machine records commonly end, and the velocity with which the tone arm is swinging toward the center P is increased in turn, giving the dog 14 a greater velocity than that of the advancing threads 5 with the result that the tooth of the dog trips on said threads pushing plate 14 and consequently lever 18 out away from the shaft 4 causing corner 24 of lever 1.8 to disengage notch 25 in the brake'plate 26 and allowing the spring 30 to set the brake shoe 86 against the flange of the turntable T, thus stopping the machine.

if it is desired to stop the operation of the machine prior to the time that the reproduccr reaches the end of the record, this may be readily effected by moving the trigger 29 on its pivot 28 away from the stop This causes the edge of trigger 29 to come in contact wit-h the post 23 on lever 18 and pushes lever 18 away from the brake plate 26 cansing the corner 24 of lever 18 to disengage notch 25 causing the brake to become set on the rim of the turntable in the same manner as when the mechanism operates at the end, of a record. The brake released by moving trigger 29 toward stop 33 until the corner 24 of lever 18 engages in notch 25. The cam portion of plate 26 between notches 25 and holds lever 18 away from shaft 4 after it is moved out by dog 14 and permits the dog to be retracted by spring 14 and set so that when the brake is again released by moving the plate 26 until corner 24 of lever 18 engages in notch 25, the automatic stop may operate upon the tone arm again being accelerated at the end of the record.

Fig. 4 is another embodiment of the invention. In this form, a collar 41 bearing threads 42 is mounted on shaft 40 so that it will move longitudinally on shaft 40 but is prevented from rotating upon the shaft by splines. On the collar bearing the threads is also attached a turret gear 43 bearing teeth 44 to engage teeth 45 cut on lever 46. These teeth are normally held out of engagement by a light spring 47 pressing the collar in the direction of the gear 3. The lever 6' is pivoted near its center at 7 and bears on its end a link 48 pivoted to it at 49. This link 48 in turn has pivoted to it a dog 51. Spring 50 holds the dog 51 in constant contact with the stop 52 which is on the link 48. Spring 53 keeps the dog constantly in contact with the threaded collar 41. Normally the dog moves from left to right at a velocity equal to or slightly slower than the threads on the collar 41 travel. When .llO

Ill

the motion of the tone arm is accelerated by the end grooves in the record, the movement of the dog is accelerated to a velocity faster than the threads move. The toe of the dog being engaged in these threads moves the collar 41 on the shaft 4.0 longitudinally and engages teeth in gear 43 in the teeth on lever 46, moving it upon its pivot so that the corner disengages the notch allowing the brake to operate as in the preferred form.

Figure 5 is another embodiment of the invention. The shaft is mounted on a lever 61 which is pivoted on the post I This lever is normally held in the position illustrated by the tension of the spring 62. Lever 6 has a dog (33 mounted on it at the pivot (54-. The dog is held in constant contact with the shaft 60 which bears the threads 65 by means of the spring (16. The operation is similar as in the other models except that when the velocity of the dog is accelerated to a velocity faster than the threads travel, the toe of the dog pushes the lever 60 away from the lever 6 causing the post 67 to come in contact with lever 68 moving it upon its pivot 69 so that the corner 7O disengages slot 25 and permits the brake to operate as before.

The form shown in Fig. 4 has the advantage of utilizing the power directly from the record driving shaft to trip the brake, while the form in. Fig. 5 is more simple and requires fewer parts than the others.

Having described my invention, what I claim and desire to secure by Letters Patent of the United States is:

1.. An automatic stop for phonographs having a rotary record support, and a travcling tone arm, comprising a shaft driven at a speed proportional to that of the record support, means operatively connected to said tone arm whereby movement of said tone arm causes said means to move lengthwise of said shaft, stop mechanism for stopping the rotation of said record support and interconnecting means between said first named means and said shaft for actuating said stop mechanism upon an increase in speed of said tone arm.

2. In an automatic stop for phonographs, a rotating element, a tone arm co-acting therewith and having an angular speed proportional to the speed of rotation of said rotating element, a shaft driven from said rotatable elemen a member movable lengthwise of said shaft by said tone arm, means for stopping said rotating element and interconnecting means between said member and said shaft operable upon an increase of the angular speed of said tone arm relatively to the speed of said element to actuate said stopping means.

3. In an automatic stop for phonographs, a rotating element, a tone arm co-acting therewith and having an angular speed proportional to the speed of rotation of said rotating element, a shaft driven from said rotatable element, a member movable lengthwise of said shaft by said tone arm, means for stopping said rotating element and interconnecting means between said member and said shaft operable upon an increase. of the angular speed of said tone arm relatively to the speed of said element to actuate said stopping means, said interconnecting means including a tripping dog on said member and means carried by said shaft for trioping said dog.

4. In an automatic stop device for talking machines, a rotatable record support, a tone arm adapted to be moved by engagement of the needle carried thereby with a record on saic support at a predetermined rate, means for stopping the rotation of said support, and means for actuating said stopping means including a member connected with said support to rotate at a speed proportional thereto, a trip member movable under the influence of said tone arm adapted to engage said first named member to actuate said step means upon an increase in the rate of movement of said tone arm.

5. In an automatic stop device for talking machines, a rotatable record support, a tone arm adapted to be moved by engagement of theneedle carried thereby with. a record on said support at a predetermined rate, means for stopping the rotation of said support, and means for actuating said stopping means including a screwthreadcd member connected with said support to 1'0- tate at a speed proportional thereto, a trip member movable under the influence of said tone arm adapted to engage the threads of said first named member to actuate said step means upon an increase in the rate of movement of said tone arm.

6. The combination with a talking machine having a rotatable record support and sound reproducing means adapted for moven'ient across said support, of stop mechanism for said support, and means for actuating said stop mechanism comprising a member cooperative with the stop mechanism, a shaft connected with said record support to retate at a speed proportional thereto, and means actuated by said shaft upon an in crease in the speed of movement of said sound reproducing means above a predetermined rate to move said member and cause actuation of said step mechanism.

7. The combination with a talking machine having a rotatable record support and sound reproducing means adapted for mova ment across said support, of stop mechanism for said support, and means for actuating said step mechanism comprising a member cooperative with the stop mechanism, a shaft connected with said record support to rotate Ell llO

to said shaft by said sound reproducing means.

8. he combination with a talking machine having a rotatable record support and sound reproducing means adapted movement across said support, of stop mechanism for said support, and means for actuating said step mechanism comprising a member cooperative with the stop mechanism, a shaft connected with. said record support to rotate at a speed proportional thereto, and means actuated by said shaft upon an increase in the speed of movement of said sound reproducing means above a predetermined rate to move said member and cause actuation of said step mechanism, said last named means including a member movable lengti wise of said shaft by said sound reproducing means and screw threaded means on said' shaft engaging said member.

9. The combination with a chine having a rotatable record support ane sound ieproducing means adapted tor ment across said support, of stop mechanism for said support, and means tor actuating said stop mechanism comprising a membe cooperative with the stop n'lechanism, a second member cooperative with said record support, and means operative upon an increase in the speed of movement of said sound reproducing means relative to the speed of rotation of said record support for causing said second member to move said first named member and thereby actuate saic stop mechanism.

10. The combination with a talking machine having a rotatable record support and sound reproducing means adapted for move ment across said support, of stop mechanism for said support, and means for actuating said stop mechanism comprising a member cooperative with the stop mechanism, a second member cooperative with said record support, and a lever operative upon an in crease in the speed of movement of said sound reproducing means without increase in the speed of rotation of said support for causing said second member to move said first named member and thereby actuate said step mechanism:

11. The combination with a talking machine having a rotatable record support and sound reproducing means adapted for movement across said support, of 'stop mechanism for said support, and means for actuating said step mechanism comprising a member cooperative with the stop mechanism, a second member cooperative with said record support, and a lever operative upon an increase in the speed of movement of said sound reproducing means without increase in the speed of rotation of said support for causing said rotating member to move said first named member and thereby actuate said stop mechanism.

12. The combination with a talking machine having a rotatable record support and sound reproducing means adapted for movement across said support, control mechanism for controlling the operation of said machine and means for actuating said mechanism comprising a member cooperative with said control mechanism, av second member cooperative with said record support, and means operative upon an increase in the speed or" movement of said sound reproducing means without increase in the speed of rotaton of said. support for causing said second member to move said first named member into position to actuate said control mechanism.

l8. The combination with a talking macaine having a rotatable record support and sound reproducing means adapted for movement across said support, control mechanism for controlling the operation of said machine and means for actuating said me-hanism comprisim a member cooperative with said control mechanism, a second member moved by the rotation of said record support and means actuated by an increase in the ratio of the speed of movement of said sound reproducing means to the speed of movement of said second member for moving said first named member to actuate said control mechanism.

In witness whereof, I hereunto subscribe my name this 25th day of October A. 1)., 1927.

GERALD B. nonoms. 

